??? LS1 Heads vs LS6 Heads ???

**Speed_kills_WS6** · 02-28-2009, 03:04 PM

Ok, just ran across some LS6 heads off a 2006 GTO that were sent to Livernois Motorsports for a freshening up. I thought the 2006 GTO had the 6.0L LS2? Did they use LS6 heads?

**Firebirdjones** · 02-28-2009, 03:14 PM

Originally Posted by Speed_kills_WS6

Ok, just ran across some LS6 heads off a 2006 GTO that were sent to Livernois Motorsports for a freshening up. I thought the 2006 GTO had the 6.0L LS2? Did they use LS6 heads?

Well they used the casting number 243 heads with same D shape exhaust port design but there were some variances to what people consider the original LS6 heads.

They won't have the lightweight hollow stem (sodium filled) valves.

Also I believe the LS2 version 243 casting will have a slightly larger combustion chamber to keep compression in check on the larger 364 cubed motor,,,where as the original LS6 243 heads on the 02-03 346 cubed motor had an even tighter combustion chamber than stock LS1 heads did to bump another 1/2 point of compression out of it.

Something that a simple milling would take care of.

**Speed_kills_WS6** · 02-28-2009, 03:26 PM

Which would be the better route to take? The larger or the smaller?

**Firebirdjones** · 02-28-2009, 03:26 PM

Here ya go I found some simple combustion chamber volumes.

Typical 97 and up LS1 heads
#853
#241

Both have a combustion chamber volume of 66.67cc and produce 10:1 compression ratio.

01-02 LS6 heads
#243
Has a combustion chamber volume of 64.45cc and produces 10.5:1 compression ratio on the same 346 cube motor.

I read somewhere the combustion chamber was changed later on to run these heads on the larger 6.0 motors to keep compression reasonable. Not sure on that one. Could have been a simple piston redesign in the 6.0 as well.

**Firebirdjones** · 02-28-2009, 03:46 PM

Originally Posted by Speed_kills_WS6

Which would be the better route to take? The larger or the smaller?

I'm kinda up in the air on this one. I would love to have a set of the later model 243's in my hand and poor them to see where the combustion chamber actually falls.
I do however have a set of 243's that are dated late 2002 so they are legit LS6 corvette specific heads. I'm certain they would poor near the 64cc the books claim though.

**Speed_kills_WS6** · 03-01-2009, 08:42 AM

I also found some 243 casted heads for the 5.7L Block. They are far from a steal I'd think, but they are described as nearly new for 600 bucks. The only difference I see in the heads is the intake runner being 220cc for the 6.0L heads while the previous 5.7L is 200cc. Not sure of the volume on the combustion chamber...

**c5z28** · 03-01-2009, 01:33 PM

Originally Posted by midi_2001

If my setup was, 2001 LS1 (WS6) M6 with, SLP lid, ported TB, stock LS6 intake, unported LS6 heads (243's pic'd above), Kooks 1-3/4" LT's, Kooks ORY, Magnaflow CB and 3.73 gears, what cam would produce the most HP and torque without overkill?

And again, with the same setup but porting the 243 heads?

(Changing the springs to accomodate the cam is not a problem.)

People w/ stock heads have been know to put in ms4 cams, whch is probably over kill bu they get 400whp w/ just bolt-ons. A 224 cam is the standard for our cars, most people get just shy of 400 w/ bolt-ons, the 228 is like the bigger small cam good maners and driveability, and some go for the 232 cams which w/ those heads I would not be surprised to see 420rwhp. So a 228 is great but most wish they went bigger you could get the 232, or something around there with a biger lsa to smoothen the idle. What kind of power you looking for?

**blackSS01** · 03-01-2009, 08:20 PM

I will share my knowledge since I am doing the same exact thing with 02 243 heads. I called TSP and they told me the torquer V2 which I believe is 232 will not work with the 64cc 243 head without fly cutting the piston. TSP told me that the 228R is the cam of choice for those heads without fly cutting. Push rod length will have to be checked, and springs upgraded to at least Comp 918's. You don't want to do more then a clean up mill on the 243's unless you plan on running a small cam or fly cutting. Its give or take... Also, the 243 head has a heart shaped combustion chamber which burns more efficiently then the 241 or others. And like said before, it has D shaped exhaust ports. To gasket match port and polish, clean up mill, and check for cracks and etc... Looking at about $400 - $500 give or take depending on quite a few differences. The 243 head from the Z06 has Hollow intake valve, and sodium filled exhaust valves which are .06 mm longer then LS1 valves. Other 243 heads off of 6.0 don't have this set up.

**Speed_kills_WS6** · 03-02-2009, 07:05 AM

Found some more LS6 heads from an 02 Z06 Vette. A valve was cracked and will need a seat and guide in that chamber. The spring and retainer will also be needed. The others are completely intact. Could there be any other problems that would make these heads a no-buy?

**blackSS01** · 03-02-2009, 06:49 PM

Originally Posted by Speed_kills_WS6

Found some more LS6 heads from an 02 Z06 Vette. A valve was cracked and will need a seat and guide in that chamber. The spring and retainer will also be needed. The others are completely intact. Could there be any other problems that would make these heads a no-buy?

How much do they cost? You would want to have them checked for cracks and such but other then that, if thats all they need and are decent money I would tell you to buy them. You would want to upgrade all the springs regardless just because they only cost around $150 - $200 and are very cheap insurance (drop a valve and motor could be bye-bye) I don't know the exact price but I know valves are not the cheapest but only needing 1 I would say go for it. The power increase plus you may actually get a hair better MPG since the combustion chamber is more effiecient.

**UTVols98** · 03-02-2009, 11:23 PM

Originally Posted by Speed_kills_WS6

Found some more LS6 heads from an 02 Z06 Vette. A valve was cracked and will need a seat and guide in that chamber. The spring and retainer will also be needed. The others are completely intact. Could there be any other problems that would make these heads a no-buy?

If the heads are cracked, then don't even bother. The only reason I'd fix those is if they were 3000 dollar ported racing heads.

**Speed_kills_WS6** · 03-03-2009, 02:34 PM

Its only a valve, but I don't think I can get just one can I? I would definitely do the springs. But after its all said and done, it may be lighter on the pocket to just get heads that are complete with no problems. Just figured, what the hell...Got an LS6 intake and block, why not do the heads too. lol

**blackSS01** · 03-03-2009, 03:15 PM

Pretty much, just needs a valve do it. And you can get just 1 valve at a time, at least I can and would help you out since I am going through around the same type of shit. But if heads are cracked, fuck it, you can find others.

**Speed_kills_WS6** · 03-03-2009, 03:46 PM

They're 78 bucks right now on e-bay. I'd love to get better gas mileage, 16 around town sucks, & that's with a normal foot.

**c5z28** · 03-03-2009, 03:51 PM

Originally Posted by Speed_kills_WS6

They're 78 bucks right now on e-bay. I'd love to get better gas mileage, 16 around town sucks, & that's with a normal foot.

Sounds to good to be true

**Speed_kills_WS6** · 03-03-2009, 04:35 PM

May be. But I'm sure they'll be much more before its over with.

**Speed_kills_WS6** · 03-03-2009, 05:08 PM

I talked to the guy selling the heads. He says its just the seat and guide that have to be replaced. He said the heads themselves are fine. The springs on there now are Patriot dual springs, minus the one missing along with the retainer.

**Firebirdjones** · 03-04-2009, 09:53 AM

These are all reasons why I won't pay much for used heads unless I'm restoring a numbers matching car that needs it.

I've seen 3 different sets of LS6 heads at swap meets over the last several months for $300 or less. I picked up one set for even less with only a claimed 30,000 miles and they look nice but still......

I still won't stick them on the car until at the very least they make a trip to the machine shop to check guide wear and deck surface.
At a very minimum I'll spend money for magnafluxing,, a valve job, new springs, and possibly mill them slightly with a clean up pass. If I'm lucky I won't need guides but I'm still going to look at an easy $5-600 or more.

With that said you are getting close to the price of some of the cheaper CNC ported heads that are on the market right now.

Bottom line is if you have to pay more than $300 for LS6 heads I'd pass no matter what condition they are said to be in. Because by the time you are done you may as well spend a couple hundred more for a fresh set of CNC'd heads.

**UTVols98** · 03-04-2009, 10:12 AM

Originally Posted by blackSS01

I called TSP and they told me the torquer V2 which I believe is 232 will not work with the 64cc 243 head without fly cutting the piston.

Whoever told you that is full of shit. For 59cc chambers, yes. Not for the stock 64cc chamber no, you don't have to flycut with the Torquer V2. I basically have the same cam and I was borderline flycutting with the milled 59cc heads. The 64's I would be fine.